OPENFLOW refers to converting a data packet forwarding process originally controlled by a switch/router to a data packet forwarding process completed by both an OPENFLOW switch (OFS) and an OPENFLOW control server (OFC) in order to separate data forwarding from routing control.
The OFS maintains a flow table, and performs forwarding only according to the flow table. Generation, maintenance, and delivery of the flow table are implemented by the OFC. The OFS may receive a flow rule delivered by the OFC, and save the flow rule in the flow table. The flow table may be multiple flow tables, each flow table includes multiple entries, and each entry is a flow rule. As shown in FIG. 1, the entry may include a match field (designated as Match Fields and include input port (In Port), virtual local area network (VLAN), source Internet Protocol (IP) address (Src IP), destination IP address (Dst IP), source media access control (MAC) address (Src MAC), destination MAC address (Dst MAC), and so on), a counter (designated as Counters), and an instruction set (designated as Actions). The match field is used to match a received data packet, the counter records statistics information indicating that the entry matches a data packet, and the instruction set determines how to forward a data packet.
Currently, in a Software Defined Network (SDN) mode, for ease of management, a hardware learning function and a flow table management function of an OFS are disabled. When the OFS cannot find a corresponding forwarding rule for a received data packet, the OFS forwards the data packet to an OFC. The OFC determines a forwarding action of the packet, and delivers a new forwarding rule to the OFS. Then, the OFS forwards the data packet according to the forwarding rule.
Disadvantages include that when an OFC performs determining on a new data packet (that is, a data packet whose corresponding forwarding rule cannot be found by querying a flow table) received by an OFS, and consequently, processing efficiency of the new data packet is reduced. In addition, if a link between the OFS and the OFC is interrupted, the OFS cannot process the received new data packet, and consequently, network performance is reduced.